Oliver Stone's portrait of Fidel Castro is an occasion in and of itself. Lively and compulsively watchable, Stone's first documentary benefits from a mutually respectful, borderline chummy relationship between subject and interlocutor, in that Castro seems to have let down his defenses, as much as is possible, and taken a come-what-may attitude toward his American guest's far-ranging and sometimes irrepressibly blunt questions. Stone, who boiled thirty hours of footage down to a little more than ninety minutes, keeps things moving as the setting changes from the back seat of the leader's aging Mercedes sedan to various restaurants, rooms, and even Old Havana.